Assignment

1. All of the following, except one, are functions of lymph nodes. Which is NOT?

A. Lymph nodes act like a filter in the kitchen sink to pull invading pathogens out of the lymph fluid and degrade them.

B. Lymph nodes act like a filter in the kitchen sink to pull invading pathogens out of the blood and degrade them.

C. Scan for invading pathogens: Macrophages can present antigens to B- and T-cells in the lymph node to warn them of invading pathogens in the nearby tissues.

D. Fluid that has passed through the lymph nodes will be delivered back to the blood through the thoracic duct.

2. Our bodies have the capacity to make unique antibodies that can recognize billions of foreign antigens. Yet, we don't carry billions of unique genes to make these antibodies. It would completely overburden our cells to carry that many genes. Our immune cells have developed a clever trick to randomly generate these billions of antibodies through chromosomal rearrangement. Briefly explain the genetic basis of antibody diversity. Essay.

3. What cell surface molecule is a characteristic marker for T helper cells?

NOTE: in this question the "-" means minus, indicating that the indicated receptor is absent from that cell type. The "+" means positive, meaning that the cell type contains the receptor.

A. CD4-
B. CD4+
C. CD8-
D. CD8+

4. What type of lymphocyte generates antibodies?

A. Macrophages
B. T-cells
C. Natural Killer cells
D. B-cells

5. An advantage of the adaptive immune system only is:

A. its ability to have an immediate response to pathogens that breach physical barriers
B. its ability to distinguish between self and non-self molecules
C. its ability to protect the individual from pathogens regardless of previous exposure
D. its ability to create an immunological memory after an initial response

6. Three of the following statements about adaptive immunity are TRUE, but one is FALSE? Which of the following statements is false.

A. Response is to recognized "self" antigens
B. Response is maintained by memory cells
C. Response is tailored to specific antigens
D. Response is mediated by B and T cells

7. Figure 3-14 on p. 34 of the textbook shows the difference between the secondary immune response and the primary immune response. Explain what the two curves are depicting AND why they have different shapes. Essay.

Text Book: AIDS: SCIENCE AND SOCIETY by HUNG Y. FAN, ROSS F. CONNER and LUIS P. VILLARREAL, SEVENTH EDITION.